// Copyright 2006 Google Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.


// Known Issues:
//
// * Patterns only support repeat.
// * Radial gradient are not implemented. The VML version of these look very
//   different from the canvas one.
// * Clipping paths are not implemented.
// * Coordsize. The width and height attribute have higher priority than the
//   width and height style values which isn't correct.
// * Painting mode isn't implemented.
// * Canvas width/height should is using content-box by default. IE in
//   Quirks mode will draw the canvas using border-box. Either change your
//   doctype to HTML5
//   (http://www.whatwg.org/specs/web-apps/current-work/#the-doctype)
//   or use Box Sizing Behavior from WebFX
//   (http://webfx.eae.net/dhtml/boxsizing/boxsizing.html)
// * Non uniform scaling does not correctly scale strokes.
// * Optimize. There is always room for speed improvements.

// AMD by kener.linfeng@gmail.com
define(function (require) {

// Only add this code if we do not already have a canvas implementation
    if (!document.createElement('canvas').getContext) {

        (function () {

            // alias some functions to make (compiled) code shorter
            var m = Math;
            var mr = m.round;
            var ms = m.sin;
            var mc = m.cos;
            var abs = m.abs;
            var sqrt = m.sqrt;

            // this is used for sub pixel precision
            var Z = 10;
            var Z2 = Z / 2;

            var IE_VERSION = +navigator.userAgent.match(/MSIE ([\d.]+)?/)[1];

            /**
             * This funtion is assigned to the <canvas> elements as element.getContext().
             * @this {HTMLElement}
             * @return {CanvasRenderingContext2D_}
             */
            function getContext() {
                return this.context_ ||
                    (this.context_ = new CanvasRenderingContext2D_(this));
            }

            var slice = Array.prototype.slice;

            /**
             * Binds a function to an object. The returned function will always use the
             * passed in {@code obj} as {@code this}.
             *
             * Example:
             *
             *   g = bind(f, obj, a, b)
             *   g(c, d) // will do f.call(obj, a, b, c, d)
             *
             * @param {Function} f The function to bind the object to
             * @param {Object} obj The object that should act as this when the function
             *     is called
             * @param {*} var_args Rest arguments that will be used as the initial
             *     arguments when the function is called
             * @return {Function} A new function that has bound this
             */
            function bind(f, obj, var_args) {
                var a = slice.call(arguments, 2);
                return function () {
                    return f.apply(obj, a.concat(slice.call(arguments)));
                };
            }

            function encodeHtmlAttribute(s) {
                return String(s).replace(/&/g, '&amp;').replace(/"/g, '&quot;');
            }

            function addNamespace(doc, prefix, urn) {
                if (!doc.namespaces[prefix]) {
                    doc.namespaces.add(prefix, urn, '#default#VML');
                }
            }

            function addNamespacesAndStylesheet(doc) {
                addNamespace(doc, 'g_vml_', 'urn:schemas-microsoft-com:vml');
                addNamespace(doc, 'g_o_', 'urn:schemas-microsoft-com:office:office');

                // Setup default CSS.  Only add one style sheet per document
                if (!doc.styleSheets['ex_canvas_']) {
                    var ss = doc.createStyleSheet();
                    ss.owningElement.id = 'ex_canvas_';
                    ss.cssText = 'canvas{display:inline-block;overflow:hidden;' +
                        // default size is 300x150 in Gecko and Opera
                        'text-align:left;width:300px;height:150px}';
                }
            }

            // Add namespaces and stylesheet at startup.
            addNamespacesAndStylesheet(document);

            var G_vmlCanvasManager_ = {
                init: function (opt_doc) {
                    var doc = opt_doc || document;
                    // Create a dummy element so that IE will allow canvas elements to be
                    // recognized.
                    doc.createElement('canvas');
                    doc.attachEvent('onreadystatechange', bind(this.init_, this, doc));
                },

                init_: function (doc) {
                    // find all canvas elements
                    var els = doc.getElementsByTagName('canvas');
                    for (var i = 0; i < els.length; i++) {
                        this.initElement(els[i]);
                    }
                },

                /**
                 * Public initializes a canvas element so that it can be used as canvas
                 * element from now on. This is called automatically before the page is
                 * loaded but if you are creating elements using createElement you need to
                 * make sure this is called on the element.
                 * @param {HTMLElement} el The canvas element to initialize.
                 * @return {HTMLElement} the element that was created.
                 */
                initElement: function (el) {
                    if (!el.getContext) {
                        el.getContext = getContext;

                        // Add namespaces and stylesheet to document of the element.
                        addNamespacesAndStylesheet(el.ownerDocument);

                        // Remove fallback content. There is no way to hide text nodes so we
                        // just remove all childNodes. We could hide all elements and remove
                        // text nodes but who really cares about the fallback content.
                        el.innerHTML = '';

                        // do not use inline function because that will leak memory
                        el.attachEvent('onpropertychange', onPropertyChange);
                        el.attachEvent('onresize', onResize);

                        var attrs = el.attributes;
                        if (attrs.width && attrs.width.specified) {
                            // TODO: use runtimeStyle and coordsize
                            // el.getContext().setWidth_(attrs.width.nodeValue);
                            el.style.width = attrs.width.nodeValue + 'px';
                        } else {
                            el.width = el.clientWidth;
                        }
                        if (attrs.height && attrs.height.specified) {
                            // TODO: use runtimeStyle and coordsize
                            // el.getContext().setHeight_(attrs.height.nodeValue);
                            el.style.height = attrs.height.nodeValue + 'px';
                        } else {
                            el.height = el.clientHeight;
                        }
                        //el.getContext().setCoordsize_()
                    }
                    return el;
                }
            };

            function onPropertyChange(e) {
                var el = e.srcElement;

                switch (e.propertyName) {
                    case 'width':
                        el.getContext().clearRect();
                        el.style.width = el.attributes.width.nodeValue + 'px';
                        // In IE8 this does not trigger onresize.
                        el.firstChild.style.width = el.clientWidth + 'px';
                        break;
                    case 'height':
                        el.getContext().clearRect();
                        el.style.height = el.attributes.height.nodeValue + 'px';
                        el.firstChild.style.height = el.clientHeight + 'px';
                        break;
                }
            }

            function onResize(e) {
                var el = e.srcElement;
                if (el.firstChild) {
                    el.firstChild.style.width = el.clientWidth + 'px';
                    el.firstChild.style.height = el.clientHeight + 'px';
                }
            }

            G_vmlCanvasManager_.init();

            // precompute "00" to "FF"
            var decToHex = [];
            for (var i = 0; i < 16; i++) {
                for (var j = 0; j < 16; j++) {
                    decToHex[i * 16 + j] = i.toString(16) + j.toString(16);
                }
            }

            function createMatrixIdentity() {
                return [
                    [1, 0, 0],
                    [0, 1, 0],
                    [0, 0, 1]
                ];
            }

            function matrixMultiply(m1, m2) {
                var result = createMatrixIdentity();

                for (var x = 0; x < 3; x++) {
                    for (var y = 0; y < 3; y++) {
                        var sum = 0;

                        for (var z = 0; z < 3; z++) {
                            sum += m1[x][z] * m2[z][y];
                        }

                        result[x][y] = sum;
                    }
                }
                return result;
            }

            function getCoords(ctx, aX, aY) {
                var m = ctx.m_;
                return {
                    x: Z * (aX * m[0][0] + aY * m[1][0] + m[2][0]) - Z2,
                    y: Z * (aX * m[0][1] + aY * m[1][1] + m[2][1]) - Z2
                };
            };

            function getSkewedCoords(ctx, aX, aY) {
                var m = ctx.m_;
                return {
                    x: Z * (aX * m[0][0] + aY * m[1][0]) - Z2,
                    y: Z * (aX * m[0][1] + aY * m[1][1]) - Z2
                };
            }

            function copyState(o1, o2) {
                o2.fillStyle = o1.fillStyle;
                o2.lineCap = o1.lineCap;
                o2.lineJoin = o1.lineJoin;
                o2.lineWidth = o1.lineWidth;
                o2.miterLimit = o1.miterLimit;
                o2.shadowBlur = o1.shadowBlur;
                o2.shadowColor = o1.shadowColor;
                o2.shadowOffsetX = o1.shadowOffsetX;
                o2.shadowOffsetY = o1.shadowOffsetY;
                o2.strokeStyle = o1.strokeStyle;
                o2.globalAlpha = o1.globalAlpha;
                o2.font = o1.font;
                o2.textAlign = o1.textAlign;
                o2.textBaseline = o1.textBaseline;
                o2.scaleX_ = o1.scaleX_;
                o2.scaleY_ = o1.scaleY_;
                o2.x_ = o1.x_;
                o2.y_ = o1.y_;
                o2.lineScale_ = o1.lineScale_;
            }

            var colorData = {
                aliceblue: '#F0F8FF',
                antiquewhite: '#FAEBD7',
                aquamarine: '#7FFFD4',
                azure: '#F0FFFF',
                beige: '#F5F5DC',
                bisque: '#FFE4C4',
                black: '#000000',
                blanchedalmond: '#FFEBCD',
                blueviolet: '#8A2BE2',
                brown: '#A52A2A',
                burlywood: '#DEB887',
                cadetblue: '#5F9EA0',
                chartreuse: '#7FFF00',
                chocolate: '#D2691E',
                coral: '#FF7F50',
                cornflowerblue: '#6495ED',
                cornsilk: '#FFF8DC',
                crimson: '#DC143C',
                cyan: '#00FFFF',
                darkblue: '#00008B',
                darkcyan: '#008B8B',
                darkgoldenrod: '#B8860B',
                darkgray: '#A9A9A9',
                darkgreen: '#006400',
                darkgrey: '#A9A9A9',
                darkkhaki: '#BDB76B',
                darkmagenta: '#8B008B',
                darkolivegreen: '#556B2F',
                darkorange: '#FF8C00',
                darkorchid: '#9932CC',
                darkred: '#8B0000',
                darksalmon: '#E9967A',
                darkseagreen: '#8FBC8F',
                darkslateblue: '#483D8B',
                darkslategray: '#2F4F4F',
                darkslategrey: '#2F4F4F',
                darkturquoise: '#00CED1',
                darkviolet: '#9400D3',
                deeppink: '#FF1493',
                deepskyblue: '#00BFFF',
                dimgray: '#696969',
                dimgrey: '#696969',
                dodgerblue: '#1E90FF',
                firebrick: '#B22222',
                floralwhite: '#FFFAF0',
                forestgreen: '#228B22',
                gainsboro: '#DCDCDC',
                ghostwhite: '#F8F8FF',
                gold: '#FFD700',
                goldenrod: '#DAA520',
                grey: '#808080',
                greenyellow: '#ADFF2F',
                honeydew: '#F0FFF0',
                hotpink: '#FF69B4',
                indianred: '#CD5C5C',
                indigo: '#4B0082',
                ivory: '#FFFFF0',
                khaki: '#F0E68C',
                lavender: '#E6E6FA',
                lavenderblush: '#FFF0F5',
                lawngreen: '#7CFC00',
                lemonchiffon: '#FFFACD',
                lightblue: '#ADD8E6',
                lightcoral: '#F08080',
                lightcyan: '#E0FFFF',
                lightgoldenrodyellow: '#FAFAD2',
                lightgreen: '#90EE90',
                lightgrey: '#D3D3D3',
                lightpink: '#FFB6C1',
                lightsalmon: '#FFA07A',
                lightseagreen: '#20B2AA',
                lightskyblue: '#87CEFA',
                lightslategray: '#778899',
                lightslategrey: '#778899',
                lightsteelblue: '#B0C4DE',
                lightyellow: '#FFFFE0',
                limegreen: '#32CD32',
                linen: '#FAF0E6',
                magenta: '#FF00FF',
                mediumaquamarine: '#66CDAA',
                mediumblue: '#0000CD',
                mediumorchid: '#BA55D3',
                mediumpurple: '#9370DB',
                mediumseagreen: '#3CB371',
                mediumslateblue: '#7B68EE',
                mediumspringgreen: '#00FA9A',
                mediumturquoise: '#48D1CC',
                mediumvioletred: '#C71585',
                midnightblue: '#191970',
                mintcream: '#F5FFFA',
                mistyrose: '#FFE4E1',
                moccasin: '#FFE4B5',
                navajowhite: '#FFDEAD',
                oldlace: '#FDF5E6',
                olivedrab: '#6B8E23',
                orange: '#FFA500',
                orangered: '#FF4500',
                orchid: '#DA70D6',
                palegoldenrod: '#EEE8AA',
                palegreen: '#98FB98',
                paleturquoise: '#AFEEEE',
                palevioletred: '#DB7093',
                papayawhip: '#FFEFD5',
                peachpuff: '#FFDAB9',
                peru: '#CD853F',
                pink: '#FFC0CB',
                plum: '#DDA0DD',
                powderblue: '#B0E0E6',
                rosybrown: '#BC8F8F',
                royalblue: '#4169E1',
                saddlebrown: '#8B4513',
                salmon: '#FA8072',
                sandybrown: '#F4A460',
                seagreen: '#2E8B57',
                seashell: '#FFF5EE',
                sienna: '#A0522D',
                skyblue: '#87CEEB',
                slateblue: '#6A5ACD',
                slategray: '#708090',
                slategrey: '#708090',
                snow: '#FFFAFA',
                springgreen: '#00FF7F',
                steelblue: '#4682B4',
                tan: '#D2B48C',
                thistle: '#D8BFD8',
                tomato: '#FF6347',
                turquoise: '#40E0D0',
                violet: '#EE82EE',
                wheat: '#F5DEB3',
                whitesmoke: '#F5F5F5',
                yellowgreen: '#9ACD32'
            };


            function getRgbHslContent(styleString) {
                var start = styleString.indexOf('(', 3);
                var end = styleString.indexOf(')', start + 1);
                var parts = styleString.substring(start + 1, end).split(',');
                // add alpha if needed
                if (parts.length != 4 || styleString.charAt(3) != 'a') {
                    parts[3] = 1;
                }
                return parts;
            }

            function percent(s) {
                return parseFloat(s) / 100;
            }

            function clamp(v, min, max) {
                return Math.min(max, Math.max(min, v));
            }

            function hslToRgb(parts) {
                var r, g, b, h, s, l;
                h = parseFloat(parts[0]) / 360 % 360;
                if (h < 0)
                    h++;
                s = clamp(percent(parts[1]), 0, 1);
                l = clamp(percent(parts[2]), 0, 1);
                if (s == 0) {
                    r = g = b = l; // achromatic
                } else {
                    var q = l < 0.5 ? l * (1 + s) : l + s - l * s;
                    var p = 2 * l - q;
                    r = hueToRgb(p, q, h + 1 / 3);
                    g = hueToRgb(p, q, h);
                    b = hueToRgb(p, q, h - 1 / 3);
                }

                return '#' + decToHex[Math.floor(r * 255)] +
                    decToHex[Math.floor(g * 255)] +
                    decToHex[Math.floor(b * 255)];
            }

            function hueToRgb(m1, m2, h) {
                if (h < 0)
                    h++;
                if (h > 1)
                    h--;

                if (6 * h < 1)
                    return m1 + (m2 - m1) * 6 * h;
                else if (2 * h < 1)
                    return m2;
                else if (3 * h < 2)
                    return m1 + (m2 - m1) * (2 / 3 - h) * 6;
                else
                    return m1;
            }

            var processStyleCache = {};

            function processStyle(styleString) {
                if (styleString in processStyleCache) {
                    return processStyleCache[styleString];
                }

                var str, alpha = 1;

                styleString = String(styleString);
                if (styleString.charAt(0) == '#') {
                    str = styleString;
                } else if (/^rgb/.test(styleString)) {
                    var parts = getRgbHslContent(styleString);
                    var str = '#', n;
                    for (var i = 0; i < 3; i++) {
                        if (parts[i].indexOf('%') != -1) {
                            n = Math.floor(percent(parts[i]) * 255);
                        } else {
                            n = +parts[i];
                        }
                        str += decToHex[clamp(n, 0, 255)];
                    }
                    alpha = +parts[3];
                } else if (/^hsl/.test(styleString)) {
                    var parts = getRgbHslContent(styleString);
                    str = hslToRgb(parts);
                    alpha = parts[3];
                } else {
                    str = colorData[styleString] || styleString;
                }
                return processStyleCache[styleString] = {color: str, alpha: alpha};
            }

            var DEFAULT_STYLE = {
                style: 'normal',
                variant: 'normal',
                weight: 'normal',
                size: 12,           //10
                family: '微软雅黑'     //'sans-serif'
            };

            // Internal text style cache
            var fontStyleCache = {};

            function processFontStyle(styleString) {
                if (fontStyleCache[styleString]) {
                    return fontStyleCache[styleString];
                }

                var el = document.createElement('div');
                var style = el.style;
                var fontFamily;
                try {
                    style.font = styleString;
                    fontFamily = style.fontFamily.split(',')[0];
                } catch (ex) {
                    // Ignore failures to set to invalid font.
                }

                return fontStyleCache[styleString] = {
                    style: style.fontStyle || DEFAULT_STYLE.style,
                    variant: style.fontVariant || DEFAULT_STYLE.variant,
                    weight: style.fontWeight || DEFAULT_STYLE.weight,
                    size: style.fontSize || DEFAULT_STYLE.size,
                    family: fontFamily || DEFAULT_STYLE.family
                };
            }

            function getComputedStyle(style, element) {
                var computedStyle = {};

                for (var p in style) {
                    computedStyle[p] = style[p];
                }

                // Compute the size
                var canvasFontSize = parseFloat(element.currentStyle.fontSize),
                    fontSize = parseFloat(style.size);

                if (typeof style.size == 'number') {
                    computedStyle.size = style.size;
                } else if (style.size.indexOf('px') != -1) {
                    computedStyle.size = fontSize;
                } else if (style.size.indexOf('em') != -1) {
                    computedStyle.size = canvasFontSize * fontSize;
                } else if (style.size.indexOf('%') != -1) {
                    computedStyle.size = (canvasFontSize / 100) * fontSize;
                } else if (style.size.indexOf('pt') != -1) {
                    computedStyle.size = fontSize / .75;
                } else {
                    computedStyle.size = canvasFontSize;
                }

                // Different scaling between normal text and VML text. This was found using
                // trial and error to get the same size as non VML text.
                //computedStyle.size *= 0.981;

                return computedStyle;
            }

            function buildStyle(style) {
                return style.style + ' ' + style.variant + ' ' + style.weight + ' ' +
                    style.size + "px '" + style.family + "'";
            }

            var lineCapMap = {
                'butt': 'flat',
                'round': 'round'
            };

            function processLineCap(lineCap) {
                return lineCapMap[lineCap] || 'square';
            }

            /**
             * This class implements CanvasRenderingContext2D interface as described by
             * the WHATWG.
             * @param {HTMLElement} canvasElement The element that the 2D context should
             * be associated with
             */
            function CanvasRenderingContext2D_(canvasElement) {
                this.m_ = createMatrixIdentity();

                this.mStack_ = [];
                this.aStack_ = [];
                this.currentPath_ = [];

                // Canvas context properties
                this.strokeStyle = '#000';
                this.fillStyle = '#000';

                this.lineWidth = 1;
                this.lineJoin = 'miter';
                this.lineCap = 'butt';
                this.miterLimit = Z * 1;
                this.globalAlpha = 1;
                // this.font = '10px sans-serif';
                this.font = '12px 微软雅黑';        // 决定还是改这吧，影响代价最小
                this.textAlign = 'left';
                this.textBaseline = 'alphabetic';
                this.canvas = canvasElement;

                var cssText = 'width:' + canvasElement.clientWidth + 'px;height:' +
                    canvasElement.clientHeight + 'px;overflow:hidden;position:absolute';
                var el = canvasElement.ownerDocument.createElement('div');
                el.style.cssText = cssText;
                canvasElement.appendChild(el);

                var overlayEl = el.cloneNode(false);
                // Use a non transparent background.
                overlayEl.style.backgroundColor = '#fff'; //red, I don't know why, it work!
                overlayEl.style.filter = 'alpha(opacity=0)';
                canvasElement.appendChild(overlayEl);

                this.element_ = el;
                this.scaleX_ = 1;
                this.scaleY_ = 1;
                this.x_ = 0;
                this.y_ = 0;
                this.lineScale_ = 1;

                this.html_ = '';
            }

            var contextPrototype = CanvasRenderingContext2D_.prototype;
            contextPrototype.clearRect = function () {
                if (this.textMeasureEl_) {
                    this.textMeasureEl_.removeNode(true);
                    this.textMeasureEl_ = null;
                }
                this.element_.innerHTML = '';
            };

            contextPrototype.flush = function () {
                this.element_.insertAdjacentHTML('beforeEnd', this.html_);
                this.html_ = '';
            }

            contextPrototype.beginPath = function () {
                // TODO: Branch current matrix so that save/restore has no effect
                //       as per safari docs.
                this.currentPath_ = [];
            };

            contextPrototype.moveTo = function (aX, aY) {
                var p = getSkewedCoords(this, aX, aY);
                p.type = 'moveTo';
                this.currentPath_.push(p);
                this.currentX_ = p.x;
                this.currentY_ = p.y;
            };

            contextPrototype.lineTo = function (aX, aY) {
                var p = getSkewedCoords(this, aX, aY);
                p.type = 'lineTo';
                this.currentPath_.push(p);

                this.currentX_ = p.x;
                this.currentY_ = p.y;
            };

            contextPrototype.bezierCurveTo = function (aCP1x, aCP1y,
                                                       aCP2x, aCP2y,
                                                       aX, aY) {
                var p = getSkewedCoords(this, aX, aY);
                var cp1 = getSkewedCoords(this, aCP1x, aCP1y);
                var cp2 = getSkewedCoords(this, aCP2x, aCP2y);
                bezierCurveTo(this, cp1, cp2, p);
            };

            // Helper function that takes the already fixed cordinates.
            function bezierCurveTo(self, cp1, cp2, p) {
                self.currentPath_.push({
                    type: 'bezierCurveTo',
                    cp1x: cp1.x,
                    cp1y: cp1.y,
                    cp2x: cp2.x,
                    cp2y: cp2.y,
                    x: p.x,
                    y: p.y
                });
                self.currentX_ = p.x;
                self.currentY_ = p.y;
            }

            contextPrototype.quadraticCurveTo = function (aCPx, aCPy, aX, aY) {
                // the following is lifted almost directly from
                // http://developer.mozilla.org/en/docs/Canvas_tutorial:Drawing_shapes

                var cp = getSkewedCoords(this, aCPx, aCPy);
                var p = getSkewedCoords(this, aX, aY);

                var cp1 = {
                    x: this.currentX_ + 2.0 / 3.0 * (cp.x - this.currentX_),
                    y: this.currentY_ + 2.0 / 3.0 * (cp.y - this.currentY_)
                };
                var cp2 = {
                    x: cp1.x + (p.x - this.currentX_) / 3.0,
                    y: cp1.y + (p.y - this.currentY_) / 3.0
                };

                bezierCurveTo(this, cp1, cp2, p);
            };

            contextPrototype.arc = function (aX, aY, aRadius,
                                             aStartAngle, aEndAngle, aClockwise) {
                aRadius *= Z;
                var arcType = aClockwise ? 'at' : 'wa';

                var xStart = aX + mc(aStartAngle) * aRadius - Z2;
                var yStart = aY + ms(aStartAngle) * aRadius - Z2;

                var xEnd = aX + mc(aEndAngle) * aRadius - Z2;
                var yEnd = aY + ms(aEndAngle) * aRadius - Z2;

                // IE won't render arches drawn counter clockwise if xStart == xEnd.
                if (xStart == xEnd && !aClockwise) {
                    xStart += 0.125; // Offset xStart by 1/80 of a pixel. Use something
                                     // that can be represented in binary
                }

                var p = getSkewedCoords(this, aX, aY);
                var pStart = getSkewedCoords(this, xStart, yStart);
                var pEnd = getSkewedCoords(this, xEnd, yEnd);

                this.currentPath_.push({
                    type: arcType,
                    x: p.x,
                    y: p.y,
                    radius: aRadius,
                    xStart: pStart.x,
                    yStart: pStart.y,
                    xEnd: pEnd.x,
                    yEnd: pEnd.y
                });

            };

            contextPrototype.rect = function (aX, aY, aWidth, aHeight) {
                this.moveTo(aX, aY);
                this.lineTo(aX + aWidth, aY);
                this.lineTo(aX + aWidth, aY + aHeight);
                this.lineTo(aX, aY + aHeight);
                this.closePath();
            };

            contextPrototype.strokeRect = function (aX, aY, aWidth, aHeight) {
                var oldPath = this.currentPath_;
                this.beginPath();

                this.moveTo(aX, aY);
                this.lineTo(aX + aWidth, aY);
                this.lineTo(aX + aWidth, aY + aHeight);
                this.lineTo(aX, aY + aHeight);
                this.closePath();
                this.stroke();

                this.currentPath_ = oldPath;
            };

            contextPrototype.fillRect = function (aX, aY, aWidth, aHeight) {
                var oldPath = this.currentPath_;
                this.beginPath();

                this.moveTo(aX, aY);
                this.lineTo(aX + aWidth, aY);
                this.lineTo(aX + aWidth, aY + aHeight);
                this.lineTo(aX, aY + aHeight);
                this.closePath();
                this.fill();

                this.currentPath_ = oldPath;
            };

            contextPrototype.createLinearGradient = function (aX0, aY0, aX1, aY1) {
                var gradient = new CanvasGradient_('gradient');
                gradient.x0_ = aX0;
                gradient.y0_ = aY0;
                gradient.x1_ = aX1;
                gradient.y1_ = aY1;
                return gradient;
            };

            contextPrototype.createRadialGradient = function (aX0, aY0, aR0,
                                                              aX1, aY1, aR1) {
                var gradient = new CanvasGradient_('gradientradial');
                gradient.x0_ = aX0;
                gradient.y0_ = aY0;
                gradient.r0_ = aR0;
                gradient.x1_ = aX1;
                gradient.y1_ = aY1;
                gradient.r1_ = aR1;
                return gradient;
            };

            contextPrototype.drawImage = function (image, var_args) {
                var dx, dy, dw, dh, sx, sy, sw, sh;

                // to find the original width we overide the width and height
                var oldRuntimeWidth = image.runtimeStyle.width;
                var oldRuntimeHeight = image.runtimeStyle.height;
                image.runtimeStyle.width = 'auto';
                image.runtimeStyle.height = 'auto';

                // get the original size
                var w = image.width;
                var h = image.height;
                var m_ = this.m_;

                // and remove overides
                image.runtimeStyle.width = oldRuntimeWidth;
                image.runtimeStyle.height = oldRuntimeHeight;

                if (arguments.length == 3) {
                    dx = arguments[1];
                    dy = arguments[2];
                    sx = sy = 0;
                    sw = dw = w;
                    sh = dh = h;
                } else if (arguments.length == 5) {
                    dx = arguments[1];
                    dy = arguments[2];
                    dw = arguments[3];
                    dh = arguments[4];
                    sx = sy = 0;
                    sw = w;
                    sh = h;
                } else if (arguments.length == 9) {
                    sx = arguments[1];
                    sy = arguments[2];
                    sw = arguments[3];
                    sh = arguments[4];
                    dx = arguments[5];
                    dy = arguments[6];
                    dw = arguments[7];
                    dh = arguments[8];
                } else {
                    throw Error('Invalid number of arguments');
                }

                var w2 = sw / 2;
                var h2 = sh / 2;

                var vmlStr = [];

                var W = 10;
                var H = 10;

                var skewed = m_[1] || m_[2];
                var cropped = sx || sy;

                var scaleX = this.scaleX_;
                var scaleY = this.scaleY_;

                var x = this.x_ + dx * scaleX;
                var y = this.y_ + dy * scaleY;
                // If filters are necessary (rotation exists), create them
                // filters are bog-slow, so only create them if abbsolutely necessary
                // The following check doesn't account for skews (which don't exist
                // in the canvas spec (yet) anyway.
                if (!skewed || !cropped) {
                    vmlStr.push('<img src="', image.src, '"',
                        'style="position:absolute;left:', x, 'px;top:', y, 'px;');
                    vmlStr.push('width:', scaleX * dw / sw * w, 'px;height:', scaleY * dh / sh * h, 'px;');
                    if (this.globalAlpha < 1) {
                        vmlStr.push('filter:alpha(opacity=', mr(this.globalAlpha * 100) + ')');
                    }
                    vmlStr.push('" />');
                } else if (skewed) {
                    // For some reason that I've now forgotten, using divs didn't work
                    vmlStr.push(' <g_vml_:group',
                        ' coordsize="', Z * W, ',', Z * H, '"',
                        ' coordorigin="0,0"',
                        ' style="width:', W, 'px;height:', H, 'px;position:absolute;');

                    var d = getCoords(this, dx, dy);
                    var filter = [];

                    // Note the 12/21 reversal
                    filter.push('M11=', this.m_[0][0] / scaleX, ',',
                        'M12=', this.m_[1][0] / scaleY, ',',
                        'M21=', this.m_[0][1] / scaleX, ',',
                        'M22=', this.m_[1][1] / scaleY, ',',
                        'Dx=', mr(d.x / Z), ',',
                        'Dy=', mr(d.y / Z), '');

                    // Bounding box calculation (need to minimize displayed area so that
                    // filters don't waste time on unused pixels.
                    var max = d;
                    var c2 = getCoords(this, dx + dw, dy);
                    var c3 = getCoords(this, dx, dy + dh);
                    var c4 = getCoords(this, dx + dw, dy + dh);

                    max.x = m.max(max.x, c2.x, c3.x, c4.x);
                    max.y = m.max(max.y, c2.y, c3.y, c4.y);

                    vmlStr.push('padding:0 ', mr(max.x / Z), 'px ', mr(max.y / Z),
                        'px 0;filter:progid:DXImageTransform.Microsoft.Matrix(',
                        filter.join(''), ", SizingMethod='clip');>");

                    if (cropped) {
                        vmlStr.push('<div style="overflow: hidden; width:', Math.ceil((dw + sx * dw / sw) * scaleX), 'px;',
                            ' height:', Math.ceil((dh + sy * dh / sh) * scaleY), 'px;',
                            ' filter:progid:DxImageTransform.Microsoft.Matrix(Dx=',
                            -sx * dw / sw * scaleX, ',Dy=', -sy * dh / sh * scaleY, ');">');
                    }

                    vmlStr.push('<img src="', image.src, '"', 'style="position:absolute;');
                    vmlStr.push('width:', scaleX * dw / sw * w, 'px;height:', scaleY * dh / sh * h, 'px;');
                    if (this.globalAlpha < 1) {
                        vmlStr.push('filter:alpha(opacity=', mr(this.globalAlpha * 100) + ')');
                    }
                    vmlStr.push('" />');
                    if (cropped) {
                        vmlStr.push('</div>');
                    }
                    vmlStr.push('</g_vml_:group>')
                } else {
                    // Apply scales to width and height
                    vmlStr.push('<div style="overflow: hidden; width:', Math.ceil((dw + sx * dw / sw) * scaleX), 'px;',
                        ' height:', Math.ceil((dh + sy * dh / sh) * scaleY), 'px;',
                        'position:absolute;left:', x, 'px;', 'top:', y, 'px;',
                        ' filter:progid:DxImageTransform.Microsoft.Matrix(Dx=',
                        -sx * dw / sw * scaleX, ',Dy=', -sy * dh / sh * scaleY, ');">');

                    vmlStr.push('<img src="', image.src, '"', 'style="position:absolute;');
                    vmlStr.push('width:', scaleX * dw / sw * w, 'px;height:', scaleY * dh / sh * h, 'px;');
                    if (this.globalAlpha < 1) {
                        vmlStr.push('filter:alpha(opacity=', mr(this.globalAlpha * 100) + ')');
                    }
                    vmlStr.push('" /></div>');
                }

                this.html_ += vmlStr.join('');
            };

            contextPrototype.stroke = function (aFill) {
                var lineStr = [];
                var lineOpen = false;

                var W = 10;
                var H = 10;

                var x_ = this.x_;
                var y_ = this.y_;

                lineStr.push('<g_vml_:shape',
                    ' filled="', !!aFill, '"',
                    ' style="position:absolute;width:', W, 'px;height:', H, 'px;', 'left:', x_, 'px;top:', y_, 'px;"',
                    ' coordorigin="0,0"',
                    ' coordsize="', Z * W, ',', Z * H, '"',
                    ' stroked="', !aFill, '"',
                    ' path="');

                var newSeq = false;
                var min = {x: null, y: null};
                var max = {x: null, y: null};

                for (var i = 0; i < this.currentPath_.length; i++) {
                    var p = this.currentPath_[i];
                    var c;

                    switch (p.type) {
                        case 'moveTo':
                            c = p;
                            lineStr.push(' m ', mr(p.x), ',', mr(p.y));
                            break;
                        case 'lineTo':
                            lineStr.push(' l ', mr(p.x), ',', mr(p.y));
                            break;
                        case 'close':
                            lineStr.push(' x ');
                            p = null;
                            break;
                        case 'bezierCurveTo':
                            lineStr.push(' c ',
                                mr(p.cp1x), ',', mr(p.cp1y), ',',
                                mr(p.cp2x), ',', mr(p.cp2y), ',',
                                mr(p.x), ',', mr(p.y));
                            break;
                        case 'at':
                        case 'wa':
                            lineStr.push(' ', p.type, ' ',
                                mr(p.x - this.scaleX_ * p.radius), ',',
                                mr(p.y - this.scaleY_ * p.radius), ' ',
                                mr(p.x + this.scaleX_ * p.radius), ',',
                                mr(p.y + this.scaleY_ * p.radius), ' ',
                                mr(p.xStart), ',', mr(p.yStart), ' ',
                                mr(p.xEnd), ',', mr(p.yEnd));
                            break;
                    }


                    // TODO: Following is broken for curves due to
                    //       move to proper paths.

                    // Figure out dimensions so we can do gradient fills
                    // properly
                    if (p) {
                        if (min.x == null || p.x < min.x) {
                            min.x = p.x;
                        }
                        if (max.x == null || p.x > max.x) {
                            max.x = p.x;
                        }
                        if (min.y == null || p.y < min.y) {
                            min.y = p.y;
                        }
                        if (max.y == null || p.y > max.y) {
                            max.y = p.y;
                        }
                    }
                }
                lineStr.push(' ">');

                if (!aFill) {
                    appendStroke(this, lineStr);
                } else {
                    appendFill(this, lineStr, min, max);
                }

                lineStr.push('</g_vml_:shape>');

                this.html_ += lineStr.join('');
            };

            function appendStroke(ctx, lineStr) {
                var a = processStyle(ctx.strokeStyle);
                var color = a.color;
                var opacity = a.alpha * ctx.globalAlpha;
                var lineWidth = ctx.lineScale_ * ctx.lineWidth;

                // VML cannot correctly render a line if the width is less than 1px.
                // In that case, we dilute the color to make the line look thinner.
                if (lineWidth < 1) {
                    opacity *= lineWidth;
                }

                lineStr.push(
                    '<g_vml_:stroke',
                    ' opacity="', opacity, '"',
                    ' joinstyle="', ctx.lineJoin, '"',
                    ' miterlimit="', ctx.miterLimit, '"',
                    ' endcap="', processLineCap(ctx.lineCap), '"',
                    ' weight="', lineWidth, 'px"',
                    ' color="', color, '" />'
                );
            }

            function appendFill(ctx, lineStr, min, max) {
                var fillStyle = ctx.fillStyle;
                var arcScaleX = ctx.scaleX_;
                var arcScaleY = ctx.scaleY_;
                var width = max.x - min.x;
                var height = max.y - min.y;
                if (fillStyle instanceof CanvasGradient_) {
                    // TODO: Gradients transformed with the transformation matrix.
                    var angle = 0;
                    var focus = {x: 0, y: 0};

                    // additional offset
                    var shift = 0;
                    // scale factor for offset
                    var expansion = 1;

                    if (fillStyle.type_ == 'gradient') {
                        var x0 = fillStyle.x0_ / arcScaleX;
                        var y0 = fillStyle.y0_ / arcScaleY;
                        var x1 = fillStyle.x1_ / arcScaleX;
                        var y1 = fillStyle.y1_ / arcScaleY;
                        var p0 = getCoords(ctx, x0, y0);
                        var p1 = getCoords(ctx, x1, y1);
                        var dx = p1.x - p0.x;
                        var dy = p1.y - p0.y;
                        angle = Math.atan2(dx, dy) * 180 / Math.PI;

                        // The angle should be a non-negative number.
                        if (angle < 0) {
                            angle += 360;
                        }

                        // Very small angles produce an unexpected result because they are
                        // converted to a scientific notation string.
                        if (angle < 1e-6) {
                            angle = 0;
                        }
                    } else {
                        var p0 = getCoords(ctx, fillStyle.x0_, fillStyle.y0_);
                        focus = {
                            x: (p0.x - min.x) / width,
                            y: (p0.y - min.y) / height
                        };

                        width /= arcScaleX * Z;
                        height /= arcScaleY * Z;
                        var dimension = m.max(width, height);
                        shift = 2 * fillStyle.r0_ / dimension;
                        expansion = 2 * fillStyle.r1_ / dimension - shift;
                    }

                    // We need to sort the color stops in ascending order by offset,
                    // otherwise IE won't interpret it correctly.
                    var stops = fillStyle.colors_;
                    stops.sort(function (cs1, cs2) {
                        return cs1.offset - cs2.offset;
                    });

                    var length = stops.length;
                    var color1 = stops[0].color;
                    var color2 = stops[length - 1].color;
                    var opacity1 = stops[0].alpha * ctx.globalAlpha;
                    var opacity2 = stops[length - 1].alpha * ctx.globalAlpha;

                    var colors = [];
                    for (var i = 0; i < length; i++) {
                        var stop = stops[i];
                        colors.push(stop.offset * expansion + shift + ' ' + stop.color);
                    }

                    // When colors attribute is used, the meanings of opacity and o:opacity2
                    // are reversed.
                    lineStr.push('<g_vml_:fill type="', fillStyle.type_, '"',
                        ' method="none" focus="100%"',
                        ' color="', color1, '"',
                        ' color2="', color2, '"',
                        ' colors="', colors.join(','), '"',
                        ' opacity="', opacity2, '"',
                        ' g_o_:opacity2="', opacity1, '"',
                        ' angle="', angle, '"',
                        ' focusposition="', focus.x, ',', focus.y, '" />');
                } else if (fillStyle instanceof CanvasPattern_) {
                    if (width && height) {
                        var deltaLeft = -min.x;
                        var deltaTop = -min.y;
                        lineStr.push('<g_vml_:fill',
                            ' position="',
                            deltaLeft / width * arcScaleX * arcScaleX, ',',
                            deltaTop / height * arcScaleY * arcScaleY, '"',
                            ' type="tile"',
                            // TODO: Figure out the correct size to fit the scale.
                            //' size="', w, 'px ', h, 'px"',
                            ' src="', fillStyle.src_, '" />');
                    }
                } else {
                    var a = processStyle(ctx.fillStyle);
                    var color = a.color;
                    var opacity = a.alpha * ctx.globalAlpha;
                    lineStr.push('<g_vml_:fill color="', color, '" opacity="', opacity,
                        '" />');
                }
            }

            contextPrototype.fill = function () {
                this.stroke(true);
            };

            contextPrototype.closePath = function () {
                this.currentPath_.push({type: 'close'});
            };

            contextPrototype.save = function () {
                var o = {};
                copyState(this, o);
                this.aStack_.push(o);
                this.mStack_.push(this.m_);
                this.m_ = matrixMultiply(createMatrixIdentity(), this.m_);
            };

            contextPrototype.restore = function () {
                if (this.aStack_.length) {
                    copyState(this.aStack_.pop(), this);
                    this.m_ = this.mStack_.pop();
                }
            };

            function matrixIsFinite(m) {
                return isFinite(m[0][0]) && isFinite(m[0][1]) &&
                    isFinite(m[1][0]) && isFinite(m[1][1]) &&
                    isFinite(m[2][0]) && isFinite(m[2][1]);
            }

            function setM(ctx, m, updateLineScale) {
                if (!matrixIsFinite(m)) {
                    return;
                }
                ctx.m_ = m;

                ctx.scaleX_ = Math.sqrt(m[0][0] * m[0][0] + m[0][1] * m[0][1]);
                ctx.scaleY_ = Math.sqrt(m[1][0] * m[1][0] + m[1][1] * m[1][1]);
                ctx.x_ = m[2][0];
                ctx.y_ = m[2][1];

                if (updateLineScale) {
                    // Get the line scale.
                    // Determinant of this.m_ means how much the area is enlarged by the
                    // transformation. So its square root can be used as a scale factor
                    // for width.
                    var det = m[0][0] * m[1][1] - m[0][1] * m[1][0];
                    ctx.lineScale_ = sqrt(abs(det));
                }
            }


            contextPrototype.translate = function (aX, aY) {
                var m1 = [
                    [1, 0, 0],
                    [0, 1, 0],
                    [aX, aY, 1]
                ];

                setM(this, matrixMultiply(m1, this.m_), false);
            };

            contextPrototype.rotate = function (aRot) {
                var c = mc(aRot);
                var s = ms(aRot);

                var m1 = [
                    [c, s, 0],
                    [-s, c, 0],
                    [0, 0, 1]
                ];

                setM(this, matrixMultiply(m1, this.m_), false);
            };


            contextPrototype.scale = function (aX, aY) {
                var m1 = [
                    [aX, 0, 0],
                    [0, aY, 0],
                    [0, 0, 1]
                ];

                setM(this, matrixMultiply(m1, this.m_), true);
            };

            contextPrototype.transform = function (m11, m12, m21, m22, dx, dy) {
                var m1 = [
                    [m11, m12, 0],
                    [m21, m22, 0],
                    [dx, dy, 1]
                ];

                setM(this, matrixMultiply(m1, this.m_), true);

            };

            contextPrototype.setTransform = function (m11, m12, m21, m22, dx, dy) {

                var m = [
                    [m11, m12, 0],
                    [m21, m22, 0],
                    [dx, dy, 1]
                ];

                setM(this, m, true);
            };
            /**
             * The text drawing function.
             * The maxWidth argument isn't taken in account, since no browser supports
             * it yet.
             */
            contextPrototype.drawText_ = function (text, x, y, maxWidth, stroke) {
                var m = this.m_,
                    delta = 1000,
                    left = 0,
                    right = delta,
                    offset = {x: 0, y: 0},
                    lineStr = [];

                var fontStyle = getComputedStyle(processFontStyle(this.font),
                    this.element_);

                var fontStyleString = buildStyle(fontStyle);

                var elementStyle = this.element_.currentStyle;
                var textAlign = this.textAlign.toLowerCase();
                switch (textAlign) {
                    case 'left':
                    case 'center':
                    case 'right':
                        break;
                    case 'end':
                        textAlign = elementStyle.direction == 'ltr' ? 'right' : 'left';
                        break;
                    case 'start':
                        textAlign = elementStyle.direction == 'rtl' ? 'right' : 'left';
                        break;
                    default:
                        textAlign = 'left';
                }

                // 1.75 is an arbitrary number, as there is no info about the text baseline
                switch (this.textBaseline) {
                    case 'hanging':
                    case 'top':
                        offset.y = fontStyle.size / 1.75;
                        break;
                    case 'middle':
                        break;
                    default:
                    case null:
                    case 'alphabetic':
                    case 'ideographic':
                    case 'bottom':
                        offset.y = -fontStyle.size / 2.25;
                        break;
                }

                switch (textAlign) {
                    case 'right':
                        left = delta;
                        right = 0.05;
                        break;
                    case 'center':
                        left = right = delta / 2;
                        break;
                }

                var d = getCoords(this, x + offset.x, y + offset.y);

                lineStr.push('<g_vml_:line from="', -left, ' 0" to="', right, ' 0.05" ',
                    ' coordsize="100 100" coordorigin="0 0"',
                    ' filled="', !stroke, '" stroked="', !!stroke,
                    '" style="position:absolute;width:1px;height:1px;">');

                if (stroke) {
                    appendStroke(this, lineStr);
                } else {
                    // TODO: Fix the min and max params.
                    appendFill(this, lineStr, {x: -left, y: 0},
                        {x: right, y: fontStyle.size});
                }

                var skewM = m[0][0].toFixed(3) + ',' + m[1][0].toFixed(3) + ',' +
                    m[0][1].toFixed(3) + ',' + m[1][1].toFixed(3) + ',0,0';

                var skewOffset = mr(d.x / Z) + ',' + mr(d.y / Z);

                lineStr.push('<g_vml_:skew on="t" matrix="', skewM, '" ',
                    ' offset="', skewOffset, '" origin="', left, ' 0" />',
                    '<g_vml_:path textpathok="true" />',
                    '<g_vml_:textpath on="true" string="',
                    encodeHtmlAttribute(text),
                    '" style="v-text-align:', textAlign,
                    ';font:', encodeHtmlAttribute(fontStyleString),
                    '" /></g_vml_:line>');

                this.html_ += lineStr.join('');
            };

            contextPrototype.fillText = function (text, x, y, maxWidth) {
                this.drawText_(text, x, y, maxWidth, false);
            };

            contextPrototype.strokeText = function (text, x, y, maxWidth) {
                this.drawText_(text, x, y, maxWidth, true);
            };

            contextPrototype.measureText = function (text) {
                if (!this.textMeasureEl_) {
                    var s = '<span style="position:absolute;' +
                        'top:-20000px;left:0;padding:0;margin:0;border:none;' +
                        'white-space:pre;"></span>';
                    this.element_.insertAdjacentHTML('beforeEnd', s);
                    this.textMeasureEl_ = this.element_.lastChild;
                }
                var doc = this.element_.ownerDocument;
                this.textMeasureEl_.innerHTML = '';
                this.textMeasureEl_.style.font = this.font;
                // Don't use innerHTML or innerText because they allow markup/whitespace.
                this.textMeasureEl_.appendChild(doc.createTextNode(text));
                return {width: this.textMeasureEl_.offsetWidth};
            };

            /******** STUBS ********/
            contextPrototype.clip = function () {
                // TODO: Implement
            };

            contextPrototype.arcTo = function () {
                // TODO: Implement
            };

            contextPrototype.createPattern = function (image, repetition) {
                return new CanvasPattern_(image, repetition);
            };

            // Gradient / Pattern Stubs
            function CanvasGradient_(aType) {
                this.type_ = aType;
                this.x0_ = 0;
                this.y0_ = 0;
                this.r0_ = 0;
                this.x1_ = 0;
                this.y1_ = 0;
                this.r1_ = 0;
                this.colors_ = [];
            }

            CanvasGradient_.prototype.addColorStop = function (aOffset, aColor) {
                aColor = processStyle(aColor);
                this.colors_.push({
                    offset: aOffset,
                    color: aColor.color,
                    alpha: aColor.alpha
                });
            };

            function CanvasPattern_(image, repetition) {
                assertImageIsValid(image);
                switch (repetition) {
                    case 'repeat':
                    case null:
                    case '':
                        this.repetition_ = 'repeat';
                        break
                    case 'repeat-x':
                    case 'repeat-y':
                    case 'no-repeat':
                        this.repetition_ = repetition;
                        break;
                    default:
                        throwException('SYNTAX_ERR');
                }

                this.src_ = image.src;
                this.width_ = image.width;
                this.height_ = image.height;
            }

            function throwException(s) {
                throw new DOMException_(s);
            }

            function assertImageIsValid(img) {
                if (!img || img.nodeType != 1 || img.tagName != 'IMG') {
                    throwException('TYPE_MISMATCH_ERR');
                }
                if (img.readyState != 'complete') {
                    throwException('INVALID_STATE_ERR');
                }
            }

            function DOMException_(s) {
                this.code = this[s];
                this.message = s + ': DOM Exception ' + this.code;
            }

            var p = DOMException_.prototype = new Error;
            p.INDEX_SIZE_ERR = 1;
            p.DOMSTRING_SIZE_ERR = 2;
            p.HIERARCHY_REQUEST_ERR = 3;
            p.WRONG_DOCUMENT_ERR = 4;
            p.INVALID_CHARACTER_ERR = 5;
            p.NO_DATA_ALLOWED_ERR = 6;
            p.NO_MODIFICATION_ALLOWED_ERR = 7;
            p.NOT_FOUND_ERR = 8;
            p.NOT_SUPPORTED_ERR = 9;
            p.INUSE_ATTRIBUTE_ERR = 10;
            p.INVALID_STATE_ERR = 11;
            p.SYNTAX_ERR = 12;
            p.INVALID_MODIFICATION_ERR = 13;
            p.NAMESPACE_ERR = 14;
            p.INVALID_ACCESS_ERR = 15;
            p.VALIDATION_ERR = 16;
            p.TYPE_MISMATCH_ERR = 17;

            // set up externs
            G_vmlCanvasManager = G_vmlCanvasManager_;
            CanvasRenderingContext2D = CanvasRenderingContext2D_;
            CanvasGradient = CanvasGradient_;
            CanvasPattern = CanvasPattern_;
            DOMException = DOMException_;
        })();

    } // if
    else { // make the canvas test simple by kener.linfeng@gmail.com
        G_vmlCanvasManager = void 0;
    }
    return G_vmlCanvasManager;
}); // define